1) FIELD OF THE INVENTION
The subject matter of the present invention relates to a liquid mixing and dispensing nozzle to be used in conjunction with a post-mix beverage dispenser.
2) DESCRIPTION OF PRIOR ART
Post-mix beverage dispensers control the flow and mixing of two or more liquids. Generally, one liquid is non-viscous such as water which is saturated with carbon dioxide (CO.sub.2) and the other liquid is a concentrate, such as a flavored syrup. The dispenser delivers the liquids into a container with the liquids mixing to comprise the beverage that is to be obtained. Ideally, the dispensing of the liquids is to be accomplished rapidly, at the proper mixture ratio, at the proper temperature, create a minimum amount of foam with good CO.sub.2 retention and is thoroughly mixed (no stratification).
The primary use of such nozzles has been in the fast food environment. The clerk that is dispensing of the beverage places a cup or glass in association with the beverage dispenser at which time the beverage dispenser is activated thereby discharging the separate liquids into the cup or glass thereby producing the resulting beverage. It is important for the clerk to achieve the dispensed beverage as quickly as possible, thereby permitting the clerk to serve as many people in the shortest amount of time. It used to be that these liquids were dispensed at three ounces per second. However, in recent years, the dispensing rate has doubled to six ounces per second. Although the speed of the dispensed beverages is increased, it has been found that the carbon dioxide (CO.sub.2) within the soda is encouraged to escape from the soda which causes a substantial amount of foam. The clerk must then wait until the foam settles and then reactivates the beverage dispensing system to achieve the desired amount of the dispensed beverage for the consumer. This waiting for the foam to settle substantially increases the time of dispensing which when compounded with the large number of consumers that are served each and every day within a normal fast food outlet, results in a most inefficient dispensing operation.
Stratification within the dispensed beverage occurs by poor mixing of the soda water and the syrup. Stratification also occurs if the soda and the syrup do not arrive simultaneously at the mixing point at the beginning of a dispensing cycle. Within prior art nozzles, the syrup is usually introduced into the soda at the exit of the nozzle with the syrup being introduced into the soda through a plurality of small passages. This prior art configuration causes the syrup to begin to dispense before the soda water which causes stratification. The force of the flow of the syrup, due to the difference in direction and velocity from that of the soda, can also cause CO.sub.2 loss and increased foam. Increased foam is the result of CO.sub.2 coming out of solution after the soda water is mixed with the syrup.
Also, prior art dispensing valves have been known to use flow regulators upstream of the control valves that are utilized to regulate the dispensing of the syrup and the soda water. These flow regulating devices are known to cause severe turbulence within the mixture which produces increased foam and pressure loss. This turbulence, along with the large pressure change, causes a substantial amount of the CO.sub.2 leaving the soda water.